Asp residues of ?DELSEED-motif are required for peptide binding in the Escherichia coli ATP synthase.

ABSTRACT: This study demonstrates the requirement of Asp-380 and Asp-386 in the ?DELSEED-motif of Escherichia coli ATP synthase for peptide binding and inhibition. We studied the inhibition profiles of wild-type and mutant E. coli ATP synthase in presence of c-terminal amide bound melittin and melittin related peptide. Melittin and melittin related peptide inhibited wild-type ATPase almost completely while only partial inhibition was observed in single mutations with replacement of Asp to Ala, Gln, or Arg. Additionally, very little or no inhibition occurred among double mutants ?D380A/?D386A, ?D380Q/?D386Q, or ?D380R/?D386R signifying that removal of one Asp residue allows limited peptide binding. Partial or substantial loss of oxidative phosphorylation among double mutants demonstrates the functional requirement of ?D380 and ?D386 Asp residues. Moreover, abrogation of wild-type E. coli cell growth and normal growth of mutant cells in presence of peptides provides strong evidence for the requirement of ?DELSEED-motif Asp residues for peptide binding. It is concluded that while presence of one Asp residue may allow partial peptide binding, both Asp residues, ?D380 and ?D386, are essential for proper peptide binding and inhibition of ATP synthase.

SUBMITTER: Ahmad Z 

PROVIDER: S-EPMC4607043 | biostudies-literature | 2015 Apr

REPOSITORIES: biostudies-literature